Method and apparatus for producing a plastic profile having a reinforcement

ABSTRACT

In the pultrusion of reinforced plastic profiles in strand form, the strands of the reinforcement are brought together in a positioning device and subsequently embedded in the plastic. The pulling of the strands of the reinforcement through the positioning device leads to an unwanted contraction and uncontrolled positioning of the reinforcement in the plastic profile. The invention envisages forming the positioning device by multiple successive positioning means, of which at least some positioning means can be periodically moved forward in the direction of production and also moved back counter to the direction of production. As a result, there is an alternating tensioning and compression of individual regions of the reinforcement. This makes exact positioning of the reinforcement in the plastic profile possible and prevents contraction of the reinforcement.

STATEMENT OF RELATED APPLICATIONS

This patent application is a division and claims the benefit of U.S.patent application Ser. No. 14/005,716 having a filing date of 10 Jan.2014, now US Patent Publication No. 20140117581 having a publicationdate of 1 May 2014, pending and allowed, which is the US National Phaseunder 35 USC 371 of International Application No. PCT/EP2012/001159having an international filing date of 15 Mar. 2012, which claimspriority on and the benefit of German Patent Application No.102011015607.0 having a filing date of 30 Mar. 2011.

BACKGROUND OF THE INVENTION

Technical Field

The invention relates to a method for producing a plastic profile havinga reinforcement, the reinforcement being passed uninterruptedly througha positioning device and a mold then following in the direction ofproduction, and the plastic profile with the reinforcement embeddedtherein being pulled by a pulling device through the positioning deviceand the mold in the direction of production, or a method for producing aplastic profile having a reinforcement, the reinforcement with theplastic embedding the latter being passed through a mold in thedirection of production. Furthermore, the invention relates to anapparatus for producing a plastic profile having a reinforcement, with aclosed mold, completely surrounding the plastic profile, and at leastone positioning device, for the reinforcement of the plastic profilearranged upstream of the mold in the direction of production of theplastic profile, or an apparatus for producing a plastic profile havinga reinforcement, with a mold that brings the plastic profile with thereinforcement lying therein into the desired form.

Prior Art

Reinforced plastic profiles have an uninterrupted reinforcement of, inparticular, fibers, woven, braided and/or knitted fabrics, which areembedded in the plastic as a matrix. The plastic may be a thermoset, orelse a thermoplastic. Reinforced plastic profiles are mostly produceduninterruptedly, in particular continuously, in a strand. This takesplace with preference by the extrusion or pultrusion process. In thiscase, the reinforcement is pulled through a positioning device andsubsequently passed through a mold. In the mold, the reinforcement andthe plastic are brought into the desired profile. The plastic profileleaving the mold is pulled off by a pulling device following the mold inthe direction of production. In this case, the reinforcement is pulledthrough the positioning device and the plastic with the reinforcementembedded therein is pulled through the mold.

In the case of the previously known production of reinforced plasticprofiles, the positionally exact introduction of a non-unidirectionalreinforcement into the plastic is particularly problematical. Thetensile forces exerted on the reinforcement by the pulling device leadto distortions of the non-unidirectional reinforcement, such as inparticular woven, nonwoven and braided fabrics. This has the effect thatthe reinforcement does not have the desired positioning in the plasticprofile to be produced. This applies in particular in the case of areinforcement with a large fiber volume.

Furthermore, previously reinforced plastic profiles with a non-straight,in particular arcuate, shape are only possible with molds that arespecifically adapted to the shape of the reinforced plastic profile tobe produced.

BRIEF SUMMARY OF THE INVENTION

The invention is thus based on the object of providing a method and anapparatus whereby the reinforcement can be embedded exactly in theplastic profile to be produced and/or reinforced plastic profiles withvarious shapes can be produced with a universal mold.

A method for achieving at least a partial aspect of the object is amethod for producing a plastic profile having a reinforcement, thereinforcement being passed uninterruptedly through a positioning deviceand a mold then following in the direction of production, and theplastic profile with the reinforcement embedded therein being pulled bya pulling device through the positioning device and the mold in thedirection of production, characterized in that the reinforcement ispulled through a positioning device with at least two successive,separate positioning means and at least one positioning means is therebymoved in relation to at least one other. Accordingly, the reinforcementis pulled through at least two separate positioning means arrangedfollowing one another upstream of the mold, seen in the direction ofproduction, at least one positioning means being relatively movable withrespect to at least one other positioning means. Preferably, all of thepositioning means that are separate from one another are movable inrelation to one another. The relative mobility of at least onepositioning means has the effect that preferably the reinforcement iscompressed phase by phase and/or portion by portion as it is pulledthrough the positioning means, and is consequently not constantlyexposed to tensile loading. This results in a snaking movement of thereinforcement through the positioning means, which has the consequenceof momentarily relieving the reinforcement of loading region by region.Deformations or distortions of the reinforcement are thereby avoided, orat least reduced, which has the consequence of a controlled introductionof the reinforcement into the plastic. In this way, a reinforced plasticprofile with a reinforcement distributed exactly over the cross sectionand positioned exactly in the cross section can be provided.

It is envisaged with preference to change periodically the distancebetween at least two positioning means following one another in thedirection of production. In particular, this can take place by the atleast one positioning means being movable back and forth alternately inthe direction of production and counter to the direction of productionin certain time intervals. As a result, the tensile loading of thereinforcement is lifted for a time alternately on opposite sides of theperiodically moved positioning means. There is preferably even a briefcompression of the reinforcement, pressed on one side and then on theother side of the periodically moved positioning means. As a result,distortions of the reinforcement, in particular transversely withrespect to the direction of production of the plastic profile, areavoided or reduced. It is particularly advantageous if all of thepositioning means are moved back and forth periodically at regular timeintervals, preferably in a phase-offset manner. Then, various portionsof the reinforcement are alternately at least relieved, preferably evenfor a short time compressed, in the region of the positioning means.

In the case of a preferred refinement of the method, it is envisaged tokeep the reinforcement taut. This can take place by securely holding thereinforcement upstream of the first positioning means, for example byretarded unwinding of the reinforcement from a supply roll and bysecurely holding the produced reinforced plastic profile by the pullingdevice. Keeping the reinforcements taut achieves the effect that, whenat least one positioning means is moved back counter to the direction ofproduction, the reinforcement or else the entire plastic profile is notpulled back through the mold or pulling device counter to the directionof production. Furthermore, keeping the reinforcement taut has theeffect that, when at least one positioning means is periodically movedback counter to the direction of production, the tensile stress in theportion of the reinforcement lying upstream of the positioning meansthat is moving back can be reduced, or possibly the reinforcement can beslightly compressed.

According to another advantageous refinement of the method, thereinforced strand of plastic is cooled in the pulling device. This alsoallows plastic profiles reinforced by the method to be produced from athermoplastic material, because then the not yet completely curedplastic profile can leave the mold without the risk of the lateralsurface of the plastic profile sticking to the molding surfaces of themold.

It is particularly advantageous to press the reinforced plastic profileleaving the mold radially together in the pulling device. The pullingdevice may then serve for the final forming of the plastic profile, thisfinal forming, or else calibration, of the plastic profile preferablytaking place during the cooling of the same, and, as a result, thelateral surface of the plastic profile not being able to stick to thesurfaces of the pulling device that come into contact with it.

In particular, the pulling device may be formed or developed such thatit can be released from the circumference of the finished, in particularcooled, plastic profile. For example, this can take place by a multipartform of the pulling device, the individual parts of the pulling devicebeing able to move apart, and thus demold the finished plastic profilein a practical manner. Conversely, when the individual parts of thepulling device are moved together, the plastic profile can be pressed,and the intended cross section can thereby be obtained exactly. Thus, acalibration of the plastic profile as it were takes place during thepressing of the plastic profile in the pulling device, to be precisepreferably before the complete curing of the plastic profile.

According to an advantageous development of the method, it is envisagednot only to move at least one positioning means but also the mold, animpregnating unit and/or the pulling device periodically back and forth.In this case, the mold may be of one part, but may also be divided intoa heating device, a gel zone region and a final reaction region.

Preferably, the periodic movement back and forth of the at least onepositioning means, of the mold and/or of the pulling device takes placein a phase-offset or phase-shifted manner, so that the tensile loadingon the reinforcement is not lifted uninterruptedly, but instead it isalways the case that only certain portions of the reinforcement arerelieved of loading, or even compressed, at different times one afterthe other or else partially at overlapping times. As a result, when theforces are applied to the reinforcement in the direction of production,and possibly partially also counter to the direction of production, whenthe plastic profile is being produced, there is a periodic change ofload on different successive regions of the reinforcement between thepulling device and the first positioning means. These changes of loadare comparable to a snaking movement.

An apparatus for achieving at least a partial aspect of the objectmentioned at the beginning is an apparatus for producing a plasticprofile having a reinforcement, with a closed mold, completelysurrounding the plastic profile, and at least one positioning device,for the reinforcement of the plastic profile, arranged upstream of themold in the direction of production of the plastic profile,characterized in that the positioning device has multiple successivepositioning means, at least one positioning means being movable back andforth in relation to at least one other positioning means. Accordingly,multiple successive positioning means are provided and at least onepositioning means is movable in relation to the at least one otherpositioning means. If the movable positioning means is momentarily movedback counter to the direction of production on the reinforcement, it“swallows up” as it were a portion of the reinforcement, whereby thetensile loading of this region of the reinforcement is momentarilylifted, or there is even a brief portion-by-portion compression of thereinforcement. Thus, according to the invention, a deformation, inparticular contraction, of the reinforcement is counteracted or acontraction of the reinforcement that has possibly occurred is reversed.

In the case of a preferred form of the apparatus, each positioning meansis formed like an orifice plate. Alternatively or additionally, it isprovided that each positioning means has a passage for the reinforcementand/or the size of the passages of the successive positioning meansdecreases in the direction of production. The orifice-plate-likepositioning means leads to a bundling of the individual components ofthe reinforcement, for example multiple strands running through. Thealternative or additional reduction in size of the passages of thesuccessive positioning means has the effect that the bundling takesplace stage by stage, by the reinforcement being reduced increasingly incross section from one positioning means to the other. The increasinglysmaller passages of the successive positioning means cause a gradual,positionally exact bundling of the individual components of thereinforcement, whereby a uniform distribution of force is produced inthe reinforcement during the production of the plastic profile.

An advantageous refinement of the apparatus provides that eachpositioning means that can be moved back and forth is periodicallymovable independently of the other positioning means. This movement ofthe respective positioning means may be performed by a drive or anactuator, it being preferred for each movable positioning means orgroups of multiple positioning means to be assigned a drive or actuatorof its or their own. The drives or actuators allow an individualmovement of the positioning means along the direction of production ofthe reinforced plastic profile. In particular, they allow an independentor specifically coordinated sequence of the movements of the positioningmeans if multiple movable positioning means are provided.

It is also provided with preference that at least one pulling devicethat can be periodically moved back and forth follows the mold in thedirection of production, the pulling device being provided in particularwith a cooling arrangement and/or consisting of multiple gripper partsthat can be moved together and apart and in the moved-together statecompletely grip around, preferably press together, the plastic profileto be produced. The pulling device thus has multiple functions. It notonly serves for the discontinuous advancement of the reinforced plasticprofile in the direction of production, but also for the cooling and/orpressing together of the plastic profile, whereby the latter iscalibrated. An apparatus with such a pulling device is also suitable forproducing the reinforced plastic profile from a thermoplastic material.

A further method for achieving at least a partial aspect of the object,which may also be a preferred development of the previously describedmethod, is a method for producing a plastic profile having areinforcement, the reinforcement with the plastic embedding the latterbeing passed through a mold in the direction of production,characterized in that the mold is formed by multiple mold portionsfollowing one another in the direction of production and respectivelyhaving a molding passage corresponding to the cross section of theplastic profile to be produced, the mold portions being displaced suchthat the longitudinal directions of the molding passages lie on thelongitudinal center axis of the plastic profile to be produced and/orrun tangentially with respect to the longitudinal center axis of theplastic profile to be produced to achieve a desired shape of the plasticprofile. According to this, the mold is formed by multiple mold portionsfollowing one another in the direction of production, each mold portionhaving a molding passage corresponding to the cross section of theplastic profile to be produced. It is also envisaged to displace themold portions as and when required such that longitudinal center axes orlongitudinal directions of the molding passages in the mold portions lieon the longitudinal center axis of the plastic profile respectively tobe produced or optionally run tangentially thereto. In this way it ispossible with one and the same mold to produce plastic profiles withdifferent shapes, in particular both straight and curved shapes.

Preferably, the molding portions are displaced in such a way that theinclinations of the longitudinal directions of the shaping passageschange. Different inclinations of the longitudinal center axes of themolding passages of different mold portions allow a plastic profile thatis curved in any way desired to be produced. The mold portions mayhowever also be aligned such that the longitudinal directions orlongitudinal center axes of their molding passages lie on an identical,straight line, in order to produce straight plastic profiles.

A preferred development of the method envisages displacing the moldportions in such a way that, in the case of plate-like mold portions,points of the longitudinal center axes of the molding passages that liein the center of the plate lie on the longitudinal center axis of theplastic profile to be produced. Then, the straight or else non-straightshape of the plastic profile is fixed in the direction of production bythese points of the longitudinal center axes of all the mold portions.

A further apparatus for achieving the object mentioned at the beginning,which may also be a preferred development of the previously describedapparatus, is an apparatus for producing a plastic profile having areinforcement, with a mold that brings the plastic profile with thereinforcement lying therein into the desired form, characterized in thatthe mold is formed by multiple mold portions following one another inthe direction of production and having molding passages corresponding tothe cross section of the plastic profile to be produced, and the size ofeach molding passage changes in the longitudinal direction of the sameor in the direction of production of the plastic profile. In the case ofthis apparatus, the mold is formed by multiple mold portions followingone another in the direction of production with molding passagescorresponding to the cross section of the plastic profile to beproduced, the size of the molding passage in each mold portion changingin the direction of production. Preferably, as a result the mold wallsof the molding passages are convexly formed, so that the moldingpassages of the mold portions have a constriction in a plane runningtransversely with respect to the direction of production or thelongitudinal axis of the plastic profile. As a result, the moldingpassage does not come into contact with the plastic profile to beproduced over its entire length, but only at its narrowest point. As aresult, a plastic profile can even be produced with tilted moldportions, to be precise then with a shape that is curved to a greater orlesser extent or is in some other way not straight, in particular of anydesired shape, in dependence on the tilting of the mold portions.

BRIEF DESCRIPTION OF THE DRAWINGS

The inventions are explained in more detail below on the basis of thedrawing, in which:

FIG. 1 shows a schematic side view of an apparatus for producing areinforced plastic profile,

FIG. 2 shows a graphic representation of the sequence of movements overtime of individual components of the apparatus of FIG. 1,

FIG. 3 shows a schematically represented section through a mold forproducing an arcuate plastic profile, and

FIG. 4 shows the mold of FIG. 3 in an arrangement for producing astraight plastic profile.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows the essential components of an apparatus for producing areinforced plastic profile. This apparatus is a pultrusion apparatus fora plastic profile 10 with a reinforcement 11. The reinforcement 11 iscompletely embedded in a plastic 12, which may be both a thermoset and athermoplastic.

The reinforcement 11 may be formed by a multiplicity of uninterruptedstrands, but also a nonwoven, woven and/or knitted fabric. Thereinforcement 11 may also consist of combinations of strands, nonwoven,knitted and/or woven fabrics. Preferably, the reinforcement 11 is formedby high-strength synthetic, glass and/or carbon fibers or strands.

The plastic profile 10 may have any desired cross sections. In thelongitudinal direction, which corresponds to the direction of production13 of the reinforced plastic profile 10, the plastic profile 10 mayeither run in a straight line, as represented in FIGS. 1 and 4, or elsebe arcuate, according to FIG. 3. In addition, the plastic profile 10 mayhave any other desired shapes in the longitudinal direction. Theinvention is therefore neither restricted to the cross section nor tothe shape of the plastic profile 10. In particular, non-straight shapesof the plastic profile 10 may be both confined to one plane(two-dimensional) or else be three-dimensional.

The apparatus shown has multiple components following one another at adistance in the direction of production 13. At the beginning of theapparatus there is a positioning device 14 for the reinforcement 11.According to the invention, the positioning device 14 is formed bymultiple positioning means following one another at a distance in thedirection of production 13. The positioning device 14 shown is formed byfour successive positioning means 15, 16, 17 and 18. However, theinvention is not restricted to this. In the simplest case, thepositioning device 14 need only have two positioning means, and it mayalso be formed by more than four positioning means 15, 16, 17, 18.

The positioning device 14 is followed in the direction of production 13by an impregnating device 25, for feeding the liquid plastic 12 to thereinforcement 11 bundled in the positioning device 14, a heating device19 with a cooled inlet 20 at the beginning, a gel zone region 21 and afinal reaction region 22. The heating device 19 with the cooled inlet20, the gel zone region 21 and the final reaction region 22 togetherform an annular, closed mold 23, surrounding the plastic profile 10, ofthe apparatus, for which purpose they may possibly be completely orpartially combined to form a single unit or possibly also multipleunits.

At a distance downstream of the final reaction region 22 of the mold 23,seen in the direction of production 13, there is a pulling device 24,which pulls the plastic profile 10 through the positioning device 14,the impregnating device 25 and the mold 23. The pulling device 24 alsoserves for keeping the reinforcement 11 taut during the entire operationof producing the plastic profile 10, by the individual component parts,for example strands, of the reinforcement 10 being subjected to arestraining force, acting counter to the holding force of the pullingdevice 24, of a device for unrolling the strands that is not shown inthe figures.

In the case of the apparatus shown here, the impregnating device 25 isassigned a discharge device 26 for excess resin that is onlyschematically represented. A further discharge device 27 is assigned tothe gel zone region 21. This discharge device 27 serves for discharginglow-viscosity resin from the already initiated reaction.

In the case of the apparatus shown here, all four positioning means 15to 18, the impregnating device 25, the individual components of the mold23 and the pulling device 24 can be moved, in particular can be movedback and forth, in the direction of production 13 and counter to thedirection of production 13 for a short time (periodically) at preferablyregular time intervals. For this purpose, each positioning means 15 to18, the impregnating device 25, the mold 23 and the pulling device 24are particularly assigned a motion element that is not shown in thefigures. This may be a reversible linear drive, the movement axis ofwhich runs in the direction of production 13. It is also conceivable tobring about the back-and-forth movements of the positioning means 15 to18, the impregnating device 25, the mold 23 and/or the pulling device 24by actuators, for example piezos.

A conceivable alternative refinement of the apparatus envisages movingthe mold 23 as a whole back and forth. Then, the individual componentsof the mold 23 carry out movements simultaneously. For this purpose, themold 23 may be formed by components that are joined together and notspaced apart from one another, by the heating device 19, the gel zoneregion 21 and the final reaction region 22 following one anotherdirectly.

The individual positioning means 15 to 18 of the positioning device 14are formed like orifice plates. For this purpose, each positioning means15, 16, 17, 18 consists of a plate running transversely with respect tothe direction of production 13. The plates may be of the same thickness,or else have different thicknesses—as in the exemplary embodimentshown—by the positioning means 17 and 18 being thicker than thepositioning means 15 and 16, to be precise approximately twice as thick.Each of the plate-like positioning means 15 to 18 has a passage 28, 29,30, 31. The reinforcement 11 is led through the passages 28, 29, 30 and31 of the positioning means 15, 16, 18 in the direction of theimpregnating device 25. The passages 28 to 31 of the individualpositioning means 15 to 18 are of different sizes. In the direction ofproduction 13, the passages 28 to 31 of the positioning means 15 to 18become increasingly smaller. The first positioning means 15 in thedirection of production 13 accordingly has the largest passage 28, whilethe last positioning means 18 before the impregnating device 25, seen inthe direction of production 13, has the smallest passage 31. Theorifice-plate-like form of the positioning means 15 to 18, with thepassages 28 to 31 becoming increasingly smaller in the direction ofproduction 13, has the effect that the reinforcement 11 is bundled bythe positioning means 15 to 18 in the direction of production 13 andincreasingly compacted, whereby, in the direction of production 13, thereinforcement 11 is brought together in a funnel-like manner in thedirection of the impregnating device 25.

In the exemplary embodiment shown in FIG. 1, the positioning means 15 to18 are spaced equally apart from one another. The intermediate spacesbetween successive positioning means 15 to 18 are approximately the samesize. In the exemplary embodiment shown, the intermediate spaces betweentwo respective positioning means 15 to 18 are approximately thethickness of the positioning means 17 or 18.

The pulling device 24 is formed such that it can be released from thefinished plastic profile 10. For this purpose, the pulling device 24has, for example, grippers that can be moved together and apart. Whenthe pulling device 24 securely holds the plastic profile 10, it can bemoved forward by the pulling device 24 in the direction of production13. When the pulling device 24 is released from the plastic profile 10,the pulling device 24 can be moved back counter to the direction ofproduction 13.

The pulling device 24 may possibly be provided with a coolingarrangement. The cooling arrangement of the pulling device 24 isprovided in particular whenever it is intended to produce with theapparatus a plastic profile 10 in which the reinforcement 11 is embeddedin a thermoplastic material 12. The pulling device 24 may be designed inparticular for producing a plastic profile 10 from a thermoplasticmaterial 12 and also for compressing the plastic profile 10 in thecircumferential direction. Then, the demolding of the plastic profile 10takes place in the compressible pulling device 24. This demolding takesplace after a calibration of the plastic profile 10. For this purpose,the pulling device 24 may be dividably formed, by consisting of two ormore parts, in particular press parts, that can be moved together andapart transversely with respect to the direction of production 13. Withthe press parts of the pulling device 24 moved together, there takesplace a demolding under pressure or calibration of the plastic profile10 surrounded all around by the press parts. With the press parts movedapart, the pulling device 24 is detached from the lateral surface of theplastic profile 10, whereby the pulling device 24 can be moved backcounter to the direction of production 13 without contacting the lateralsurface of the plastic profile 10.

Linear drives or actuators for moving the pulling device 24 forward andback are not represented in FIG. 1. Similarly, FIG. 1 does not includeany representation of such drives or actuators for moving the gel zoneregion 21, the final reaction region 22 and the heating device 19 of themold 23 and also the impregnating device 25. Such linear drives may beformed in a way known per se. The actuators may consist of piezos. Thelatter lead to relatively small traveling distances. By contrast, lineardrives allow greater traveling distances, to be precise of any desiredlength.

The method according to the invention is described in more detail belowwith reference to FIGS. 1 and 2.

In the following description of the method, it is assumed that all fourpositioning means 15 to 18, the impregnating device 25, all parts of themold 23 and the pulling device 24 can be moved back and forth in thedirection of production 13 and counter to the direction of production 13periodically by the same distance in each case, the movement of thepositioning means 15 to 18, the impregnating device 25, the parts of themold 23 and the pulling device 24 being phase-shifted. During themovement back and forth of the aforementioned movable parts of theapparatus, the reinforcement 11 is kept taut over the entire length.

In FIG. 2, the sequences of movements are represented in a time-distancediagram. The time t is plotted on the x axis and the distance s isplotted on the y axis. In the case of the time-distance diagram shownhere, it is assumed that the positioning means 15 and 16 on the one handand the positioning means 17 and 18 on the other hand are movedsimultaneously. In the time-distance diagram of FIG. 2, the sequences ofmovement of the positioning means 15 and 16, the positioning means 17and 18, the impregnating device 25, the heating device 19 with thecooled inlet 20, the gel zone region 21, the final reaction region 22and the pulling device 24 are represented one above the other from thebottom upward. The opening of the grippers of the pulling device 24 isrepresented in vertical regions. Following thereafter in time is thetime period in which the grippers of the pulling device 24 are open,represented by a cross-hatched bar. Represented alongside by verticalhatching is the phase of the closing of the grippers. The (white)regions of a longer time between the vertical bars for the opening ofthe pulling device 24, the open pulling device 24 and the closing of thepulling device 24, represent time phases in which the grippers of thepulling device 24 are closed. Each of these time phases is greater by amultiple than the time phase in which the grippers of the pulling device24 open, close and are open.

The direction of the distance s represented on the y axis in FIG. 2corresponds to the movement of the individual components of theapparatus counter to the direction of production 13. Accordingly, amovement in the direction of the y axis that is represented in FIG. 2concerns a movement counter to the direction of production 13 of theplastic profile 10.

Represented at the top in FIG. 2 is the sequence of movements of thepulling device 24. Accordingly, with its grippers open, the pullingdevice 24 moves relatively quickly counter to the direction ofproduction 13. During the subsequent closing of the grippers of thepulling device 24, the pulling device 24 is stationary. Subsequently,with the grippers closed, the pulling device 24 is slowly moved forwardin the direction of production 13, to be precise approximately in halfthe time in which the pulling device 24 is closed during a respectivemovement cycle. The movement described above of the pulling device 24 isrepeated for each movement cycle.

The movements of all the other components of the apparatus, to bespecific the final reaction region 22, the gel zone region 21, theheating device 19 with the cooled inlet 20, the impregnating device 25,the positioning means 17 and 18 and the positioning means 15 and 16,proceed in accordance with the same pattern of movements, but arephase-shifted—as can be seen from FIG. 2—to be precise with respect tothe next-following device, by half the time in which the grippers of thepulling device 24 are opened, are open and are closed (vertical bars ofFIG. 2). The final reaction region 22, upstream of the pulling device24, is stationary while the pulling device 24 is opened, is open and isclosed. Once the pulling device 24 is closed, the final reaction region22 is moved in the direction of production 13, to be precise alwaysapproximately less than half the time in which the pulling device 24 isclosed. After a brief pause, the final reaction region 22 is then movedback counter to the direction of production 13, to be precise at thesame speed and by the same distance as the final reaction region 22 waspreviously moved forward in the direction of production 13. The samemovements are carried out with the same offset in time by the gel zoneregion 21, the heating device 19 with the cooled inlet 20, theimpregnating device 25, the positioning means 17 and 18 and thepositioning means 15 and 16.

It is clear from FIG. 2 that the same movements of all the components ofthe apparatus apart from the pulling device 24 follow one another withan offset in time, but partially overlap one another. The time offset ischosen such that the movement of the positioning means 15 and 16 at thebeginning of the apparatus is offset with respect to the movement of thefinal reaction region by half the time in which the grippers of thepulling device 24 are closed.

As a departure from the representation of FIG. 2, all four positioningmeans 15 to 18 may also be moved back and forth one after the otherindependently of one another with a small time offset. It is alsoconceivable to move only two positioning means, for example thepositioning means 15 and 17 or the positioning means 16 and 18,periodically back and forth along the plastic profile 10, while theother two positioning means 15, 17 or 16, 18 are not moved back andforth.

The phased moving back and forth of the individual components of theapparatus, in particular according to FIG. 2, has the effect thatindividual regions of the reinforcement 11 are alternately subjected totensile loading or compressive loading, that is to say are compressed.It is also conceivable to perform the periodically successive movementsof individual components of the apparatus such that the tensile loadingthat is exerted on the reinforcement 11 as it passes through theapparatus is entirely or partially reduced periodically from region toregion. The tensile loads that are exerted on the reinforcement 11during the production of the plastic profile 10, changing periodicallyfrom region to region, cause a snake-like weaving of the reinforcement11 through the individual components of the apparatus, whereby theconstriction or transverse contraction exerted on the reinforcementduring the production of the plastic profile 10 is eliminated, or atleast reduced, and as a result the form of the reinforcement 11 does notchange during the production of the plastic profile 10 and the positionof the reinforcement 11 in the plastic 12 remains unchanged during theproduction of the plastic profile 10.

A method that differs from this is conceivable, one in which only thepulling device 24 and at least one of the positioning means 15 to 18 aremoved periodically back and forth with respect to the direction ofproduction 13. As a result, a periodic portion-by-portion reduction orelimination of the tensile forces exerted on the reinforcement 11 takesplace during the production of the plastic profile 10, also periodicallyallowing spaced-apart compressions to occur in the reinforcement 11. Itis also prevented in this way that the reinforcement 11 contracts or isdisplaced in an undesirable way during the bundling and compression,that is to say upstream of the impregnating device 25 and the mold 23.

FIGS. 3 and 4 show a further exemplary embodiment of the inventiondescribed above. This exemplary embodiment may also constitute anindependent invention.

In FIGS. 3 and 4, only part of an apparatus for producing the plasticprofile provided with the reinforcement 11 is schematically represented.The part concerned here is a mold 32, which can be changed in its formsuch that plastic profiles of any desired shapes can be produced withit, to be precise not only the straight plastic profile 10 that is shownin FIG. 4 but also a curved plastic profile 33, which may be bothreinforced and unreinforced. Like the plastic 12 of the plastic profile10, the plastic 12 for the plastic profile 33 may be a thermoset or athermoplastic.

The mold 32 is formed by multiple mold portions 34 following one anotherat a distance in the direction of production 13. In the exemplaryembodiment shown, the mold 32 consists of four identical mold portions34, which enclose in one piece the entire circumference of the plasticprofile 10, 33 in the manner of a ring. The mold 32 may, however, alsohave a greater or smaller number of mold portions 34, which may possiblyalso be differently formed. Each mold portion 34, which in the exemplaryembodiment shown is formed in the manner of a plate, is provided with acentral molding passage 35. In the present case, all the moldingpassages 35 are identically formed. However, it is also conceivable thatthe molding passages 35 of at least some mold portions 34 aredifferently formed.

The molding passage 35 in each mold portion 34 is provided with aprofile or shape that changes in the direction of production 13. In theexemplary embodiment of FIGS. 3 and 4, the narrowest point of eachmolding passage 35 is in the center of the plate-like mold portion 34.From here, the molding passage 35 widens toward the opposing outersurfaces of the respective mold portion 34, so that the contour of eachmolding passage 35 is uniformly convex. In FIGS. 3 and 4, the crosssection of each molding passage 35 is of an arcuate form, to be precisean approximately semicircular form. However, there may also be othercross sections, for example triangular cross sections, elliptical crosssections or the like. At least at the narrowest point in the center ofthe mold portion 34 concerned, the molding passage 35 corresponds to thecross section of the plastic profile 10 to be produced.

The fact that the size of each molding passage 35 changes in thelongitudinal direction 36 of the respective molding passage 35 meansthat the circumferential surface of each molding passage 35 is convex.Only in a plane in which the narrowest point of the respective moldingpassage 35 lies, in the exemplary embodiment shown the center of therespective mold portion 34, is there contact of the molding passage 35with the outer surface of the plastic profile 10 to be produced. Thismakes it possible to position the mold portions 34 obliquely in such away that the longitudinal direction 36 of the molding passage 35 of eachmold portion 34 runs in different directions. This allows the productionnot only of straight plastic profiles 10 but also of a curved plasticprofile 33 (FIG. 3). By obliquely positioning the mold portions 34appropriately, a plastic profile with any desired shape can be produced.The plastic profile may be both two-dimensionally andthree-dimensionally curved. In the exemplary embodiment of FIG. 4, allthe mold portions 34 of the mold 32 run parallel to one another at asmall distance, whereby the longitudinal directions 36 of all themolding passages 35 lie on a common straight line, to be specific thecenter line of the straight plastic profile 10 to be produced. If, onthe other hand, the mold portions 34 are tilted according to therepresentation in FIG. 3, to be precise preferably to the same extentand in the same direction, the curved plastic profile 33 that is shownin FIG. 3 is produced. Then, the longitudinal directions 36 of themolding passages 35 of the mold portions 34 run tangentially withrespect to the longitudinal center axis 37 of the curved plastic profile33.

With preference, the mold portions 34 are formed from differentmaterials, in order to reduce the friction on the lateral surface or thematrix of the plastic profile 10, 33 to be produced. For example, thefirst mold portion 34 in the direction of production 13 could be formedfrom steel, preferably high-grade steel. The then-following mold portion34 could be formed from copper. The other mold portions 34 may be formedfrom thermoplastic material, for example polyoxymethylene, or aluminum.

It is also conceivable to cool all or only selected mold portions 34, inparticular the mold portions 34 lying downstream in the direction ofproduction 13, and/or to heat at least the first mold portions 34.

The method for producing plastic profiles 10, 33 having any desiredshapes proceeds as follows with the mold 32 described above:

Depending on the desired form of the plastic profile 10, 33 to beproduced, the mold portions 34 are aligned in relation to one anotherand fixed. For the production of the straight plastic profile 10, allthe mold portions 34 are arranged in relation to one another such thatthey run parallel to one another, to be precise preferably at equaldistances. The longitudinal center axes or longitudinal directions 36 ofthe molding passages 35 of all the mold portions 34 then lie on a commonline, which corresponds to the straight longitudinal center axis 37 ofthe non-curved plastic profile 10 (FIG. 4).

If, on the other hand, the curved plastic profile 33 is to be produced,preferably all the mold portions 34 are tilted uniformly and in the samedirection in relation to one another, to be precise such that the centerplanes of all the mold portions 34 converge at a common point. In thiscase, the longitudinal center axes 36 of the molding passages 35 of allthe mold portions 34 lie tangentially on the arcuate longitudinal centeraxis 37 of the plastic profile 33. If the mold portions 34 are tiltedmulti-axially, three-dimensionally curved plastic profiles can beproduced.

It is conceivable that at least one mold portion 34, the first withrespect to the direction of production 13, is heated, while at least thelast mold portion 34 serves for cooling the plastic profile 10 or 33 tobe produced. The mold portions 34 to be cooled may be formed from amaterial having a relatively smooth and slidable surface, for example anappropriate plastic, but also aluminum, bronze or copper. By contrast,the respectively heated mold portion is formed from a heat-resistantmaterial, for example steel, in particular a chrome-like steel, butpossibly also aluminum, copper or bronze.

LIST OF DESIGNATIONS

-   10 plastic profile-   11 reinforcement-   12 plastic-   13 direction of production-   14 positioning device-   15 positioning means-   16 positioning means-   17 positioning means-   18 positioning means-   19 heating device-   20 cooled inlet-   21 gel zone region-   22 final reaction region-   23 mold-   24 pulling device-   25 impregnating device-   26 discharge device-   27 discharge device-   28 passage-   29 passage-   30 passage-   31 passage-   32 mold-   33 plastic profile-   34 mold portion-   35 molding passage-   36 longitudinal direction-   37 longitudinal center axis

What is claimed is:
 1. An apparatus for producing a plastic profile (10,33) having a reinforcement (11), comprising: a closed mold (23, 32),completely surrounding the plastic profile (10, 33); at least onepositioning device (14), for the reinforcement (11) of the plasticprofile (10, 33), arranged upstream of the mold (23, 32) in thedirection of production (13) of the plastic profile (10, 33) thepositioning device (14) having multiple successive positioning means(15, 16, 17, 18); and at least one of the positioning means (15, 16, 17,18) being movable back and forth in relation to at least one otherpositioning means (15, 16, 17, 18).
 2. The apparatus as claimed in claim1, wherein each positioning means (15, 16, 17, 18) is formed like anorifice plate and/or each positioning means (15, 16, 17, 18) has apassage (28, 29, 30, 31) for the reinforcement (11) and the passages(28, 29, 30, 31) in the positioning means (15, 16, 17, 18) following oneanother in the direction of production (13) become smaller in thedirection of production (13).
 3. The apparatus as claimed in claim 1,wherein the positioning means (15, 16, 17, 18) that is movable back andforth is periodically moved independently of the other positioning means(15, 16, 17, 18).
 4. The apparatus as claimed in claim 1, furthercomprising at least one pulling device (24) that can be periodicallymoved back and forth, wherein the at least one pulling device (24)follows the mold (23, 32) in the direction of production (13).
 5. Theapparatus as claimed in claim 3, wherein the positioning means (15, 16,17, 18) that is movable back and forth is periodically movedindependently of the other positioning means (15, 16, 17, 18) by a driveor actuator of its own.
 6. The apparatus as claimed in claim 4, whereinthe pulling device (24) has a cooling arrangement and/or consists ofmultiple gripper parts that can be moved together and apart and in thepressed-together state completely grip around the plastic profile (10,33) to be produced.
 7. A method for producing a plastic profile (10, 33)having a reinforcement (11), comprising: passing the reinforcement (11)with plastic (12) embedding the reinforcement through a mold (23, 32) inthe direction of production (13); forming the mold (32) with multiplemold portions (34) following one another in the direction of production(13) and respectively having a molding passage (35) corresponding to thecross section of the plastic profile (10, 33) to be produced; anddisplacing the mold portions (34) such that the longitudinal directions(36) of the molding passages (35) lie on a longitudinal center axis ofthe plastic profile (10) to be produced and/or run tangentially withrespect to the longitudinal center axis (37) of the plastic profile (33)to be produced to achieve a desired shape of the plastic profile (10,33).
 8. The method as claimed in claim 7, wherein the mold portions (34)are displaced in such a way that the inclinations of the longitudinaldirections (36) of the molding passages (35) change.
 9. The method asclaimed in claim 7, wherein the mold portions (34) are displaced in sucha way that, in the case of plate-like mold portions (34), points of themolding passages (35) that lie in the center of the plate lie on thelongitudinal center axis (37) of each plastic profile (10, 33) to beproduced.
 10. The method as claimed in claim 8, wherein the moldportions (34) are displaced in such a way that, in the case ofplate-like mold portions (34), points of the molding passages (35) thatlie in the center of the plate lie on the longitudinal center axis (37)of each plastic profile (10, 33) to be produced.
 11. An apparatus forproducing a plastic profile (10, 33) having a reinforcement (11),comprising a mold (32) that brings the plastic profile (10, 33) with thereinforcement (11) lying therein into the desired form, wherein the mold(32) is formed by multiple mold portions (34) following one another in adirection of production (13) and having molding passages (35)corresponding to the cross section of the plastic profile (10, 33) to beproduced, and the size of each molding passage (35) changes in thelongitudinal direction (36) of the same or in the direction ofproduction (13) of the plastic profile (10, 33).
 12. The apparatus asclaimed in claim 11, wherein the mold portions (34) are formed as moldplates, the molding passages (35) that extend transversely through themold plates being smallest approximately in the center of the respectivemold plate and increasing in size increasingly toward opposing mainsurfaces of the molding plates.
 13. The apparatus as claimed in claim11, wherein the mold portions (34) can be tilted, by the longitudinaldirection (36) of the molding passage (35) in the respective moldportion (34), namely the respective mold plate.
 14. The apparatus asclaimed in claim 13, wherein the respective mold plate is variable ininclination.